Washing machine

ABSTRACT

A washing machine having a water supply unit provided with a branch pipe. The washing machine includes a main body, a tub provided within the main body, a water supply hose connected to a water supply source to supply water to the tub, the water supply unit including channels defined by at least one inlet and at least one outlet and at least one structure discriminated from the channels, at least one of the at least one inlet and the at least one outlet being connected to the water supply hose, and a branch pipe provided on the water supply unit to allow a portion of water introduced into the water supply unit to branch off and be discharged to the outside of the water supply unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Korean PatentApplication No. 2010-0073968, filed on Jul. 30, 2010, and No.2010-0091569, filed on Sep. 17, 2010, in the Korean IntellectualProperty Office, the disclosures of which are incorporated herein byreference.

BACKGROUND

1. Field

Embodiments relate to a washing machine having a water supply unitprovided with a branch pipe allowing a portion of water supplied to atub to be utilized for purposes other than washing.

2. Description of the Related Art

In general, a washing machine is an apparatus which includes a drum toreceive laundry, for example, such as clothes, and a motor to drive thedrum, and performs a series of washing, rinsing and spin-drying cyclesusing rotation of the drum.

The washing machine is provided with a door glass on the front surfacethereof such that the inside of the washing machine can be viewed.During the washing or rinsing cycle, detergents used in washing orcontaminants separated from the laundry may stick to the door glass.These detergents or contaminants not only provide a bad impression to auser but also contact the laundry and thus re-contaminate the laundrywhile the laundry is taken out of the drum after completing washing ofthe laundry.

The washing machine receives water required to perform washing orrinsing of the laundry from an external water supply source. For thispurpose, the washing machine is provided with water supply hosesconnected to the external water supply source.

During operation of the washing machine, water containing the detergentsor contaminants may flow backward to the water supply hoses. Thebackflow of water is introduced into the external water supply sourceand is then contaminates the external water supply source, therebycausing environmental problems.

SUMMARY

Therefore, it is an aspect to provide a washing machine having a watersupply unit provided with a branch pipe.

Additional aspects of the invention will be set forth in part in thedescription which follows and will be apparent from the description, ormay be learned by practice of the invention.

In accordance with one aspect, a washing machine includes a main body, atub provided within the main body, a water supply hose connected to awater supply source to supply water to the tub, a water supply unitincluding channels defined by at least one inlet and at least one outletand at least one structure discriminated from the channels, at least oneof the at least one inlet and the at least one outlet being connected tothe water supply hose, and a branch pipe provided on the water supplyunit to allow a portion of water introduced into the water supply unitto branch off and be discharged to the outside of the water supply unit.

The water supply unit may be a detergent supply device provided tosupply detergents to the tub.

The detergent supply device may include at least one inlet pipeprotruded from the at least one inlet so as to be connected to the watersupply hose, and the branch pipe may branch off from the at least oneinlet pipe.

The at least one inlet may include a first inlet into which water isintroduced during a main washing cycle and a second inlet into whichwater is introduced during a preliminary washing cycle, the at least oneinlet pipe may include a first inlet pipe protruded from the first inletand a second inlet pipe protruded from the second inlet, and the branchpipe may be fixed to the second inlet pipe so as to communicate with thesecond inlet pipe.

The branch pipe may be extended downwards.

A cross-sectional area of the branch pipe may be smaller than across-sectional area of the at least one inlet pipe from which thebranch pipe branches off.

A length of the second inlet pipe may be greater than a length of thefirst inlet pipe.

The water supply unit may be a backflow prevention device provided toprevent wash water from flowing backward and being introduced into thewater supply source.

The backflow prevention device may include a case provided with the atleast one inlet and the at least one outlet and a backflow blocking unitdisposed within the case to block a backflow of water into the at leastone inlet, and the at least one inlet may be connected to the watersupply hose and the at least one outlet may be a plurality of outletsprovided so as to discharge water in different directions.

The case may include a nozzle part provided with the at least one inletand a connector part provided with the at least one outlet.

The nozzle part and the connector part may be coupled with each other byscrew connection.

The backflow blocking unit may include a moving member moving within thecase according to a water flow so as to selectively open and close theat least one inlet.

The backflow blocking unit may further include a separation memberdisposed around the at least one outlet so as to separate the movingmember from the at least one outlet.

The backflow blocking unit may further include an inclined surface partformed on the inner wall of the case so as to guide the moving member tothe at least one inlet.

The moving member may be a spherical ball having a designated diameter,and the diameter of the ball may be greater than a diameter of the atleast one inlet.

The moving member may be closely adhered to the at least one inlet dueto water pressure and close the at least one inlet when water flowsbackward in the direction of the at least one inlet.

The case may include an outlet pipe connected to one of the plurality ofoutlets and protruded to the outside of the case, and at least one ofthe plurality of outlets may be formed on the side wall of the outletpipe.

The branch pipe may communicate with the at least one of the pluralityof outlets formed on the side wall of the outlet pipe and be protrudedto the outside of the outlet pipe.

The washing machine may further include a door to open and close themain body and a door washing hose to guide water to the rear surface ofthe door, and the branch pipe may be connected to the door washing hose.

In accordance with another aspect, a washing machine includes a mainbody, a tub provided within the main body, a water supply hose connectedto a water supply source to supply water to the tub, and a backflowprevention device mounted on the water supply hose to prevent wash waterin the tub from flowing backward and being introduced into the watersupply source, wherein the backflow prevention device includes abackflow prevention part provided with an inlet and an outlet, an inletchannel communicating with the inlet, outlet channels communicating withthe outlet, and a backflow blocking unit disposed in the backflowprevention part to prevent water from flowing backward into the inletchannel, and the outlet channels include a first outlet channel and asecond outlet channel formed separately from the first outlet channel.

The second outlet channel may branch off from the first outlet channel.

The second outlet channel may directly communicate with the backflowprevention part.

In accordance with another aspect, a washing machine includes a mainbody, a tub provided within the main body, a water supply hose connectedto a water supply source to supply water to the tub, and a detergentsupply device connected to the water supply hose to supply detergents tothe tub, wherein the detergent supply device includes a housing, inletpipes protruded to the outside of the housing so as to be connected tothe water supply hose, and a branch pipe branching off from at least oneof the inlet pipes.

In accordance with another aspect, a washing machine includes a mainbody provided with an inlet through which laundry is put into the mainbody, a tub formed within the main body and provided with an openingcorresponding to the inlet, a door to open and close the inlet, a gasketto shield a space between the inlet and the opening, a water supply hoseconnected to a water supply source to supply water to the tub, a doorwashing hose connected to a wash water spray hole formed on the gasket,and a backflow prevention device mounted on the water supply hose toprevent wash water from flowing backward along the water supply hose andbeing introduced into the water supply source, wherein the backflowprevention device includes a case, an inlet pipe and an outlet pipecommunicating with the inside of the case and protruded to the outsideof the case, a backflow blocking unit disposed at the inside of thecase, and a branch pipe forming a channel separately from the outletpipe, and the branch pipe is connected to the door washing hose.

In accordance with another aspect, a detergent supply device includes ahousing, a detergent container provided within the housing so as toreceive detergents, inlet pipes protruded to the outside of the housingso as to supply water to the detergent container, and a branch pipefixed to at least one of the inlet pipes so as to allow a portion ofwater introduced into the inlet pipe to branch off.

In accordance with a further aspect, a backflow prevention deviceincludes a case including a nozzle part provided with an inlet and aconnector part provided with an outlet, a backflow blocking unitdisposed within the case to prevent water within the case from flowingbackward and being introduced into the inlet, and a branch hole forminga channel separately from the outlet, wherein the nozzle part and theconnector part are coupled with each other by screw connection.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the invention will become apparent andmore readily appreciated from the following description of theembodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a cross-sectional view illustrating a main configuration of awashing machine in accordance with one embodiment;

FIG. 2 is an exploded perspective view of a detergent supply device ofthe washing machine in accordance with the embodiment;

FIG. 3A is a plan view illustrating water supply channels of thedetergent supply device shown in FIG. 2;

FIG. 3B is a cross-sectional view illustrating an inlet pipe and abranch pipe of the detergent supply device shown in FIG. 2;

FIG. 4A is a cross-sectional view illustrating a main configuration of awashing machine in accordance with another embodiment;

FIG. 4B is a view illustrating connection between a backflow preventiondevice and a detergent supply device of the washing machine inaccordance with the embodiment;

FIG. 5 is an exploded perspective view of the backflow prevention devicein accordance with the embodiment;

FIG. 6A is a cross-sectional view of the backflow prevention device inaccordance with the embodiment;

FIG. 6B is a cross-sectional view of a backflow prevention device inaccordance with a further embodiment; and

FIGS. 7A and 7B are views illustrating operation of a backflowprevention device in accordance with one embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments, examples ofwhich are illustrated in the accompanying drawings, wherein likereference numerals refer to like elements throughout.

FIG. 1 is a cross-sectional view illustrating a main configuration of awashing machine in accordance with one embodiment.

As shown in FIG. 1, a washing machine 1 in accordance with thisembodiment includes a main body 10 forming the external appearance ofthe washing machine 1, a tub 20 disposed within the main body 10, a drum30 rotatably disposed within the tub 20, and a motor 40 to drive thedrum 30.

An inlet 14 through which laundry is put into the drum 30 is formedthrough the front surface portion of the main body 10, and is opened andclosed by a door 12 installed on the front surface portion of the mainbody 10. Further, a door glass 13 made of a transparent material ismounted along the inner circumferential surface of the door 12 such thata user may view the interior of the drum 30 with the naked eye.

An opening 21 is formed on the front surface portion of the tub 20 at aposition corresponding to the inlet 14 of the main body 10. In order toshield a space between the inlet 14 of the main body 10 and the opening21 of the tub 20, a gasket 11 connecting the inlet 14 and the opening 21is installed. The gasket 11 is fixed to the main body 10 and the tub 20,respectively. The gasket 11 may be made of an elastic material so as tocope with vibration of the tub 20.

Water supply hoses 60 to supply wash water to the tub 20 are installedabove the tub 20. One end of each of the water supply hoses 60 isconnected to an external water supply source (not shown) and the otherend of each of the water supply hoses 60 is connected to a detergentsupply device 100. Here, the other end of each of the water supply hoses60 may be connected directly to the detergent supply device 100.

The detergent supply device 100 is connected to the tub 20 through aconnection hose 64. Water supplied through the water supply hoses 60 issupplied to the detergent supply device 100 and is mixed with detergentsin the detergent supply device 100. Then, water containing thedetergents is supplied to the inside of the tub 20.

A drain pump 70 and a drain pipe 72 to discharge the water in the tub 20to the outside of the main body 10 are installed under the tub 20.

The drum 30 includes a cylindrical member 31, a front plate 32 disposedat the front part of the cylindrical member 31, and a rear plate 33disposed at the rear part of the cylindrical member 31. An opening 32 athrough which the laundry is put into the drum 30 is formed on the frontplate 32, and a drive shaft 42 to transmit drive force of the motor 40is connected to the rear plate 33.

A bearing housing 50 is installed on the rear wall of the tub 20 so asto rotatably support the drive shaft 42. The bearing housing 50 is madeof an aluminum alloy and is inserted into the rear wall of the tub 20when the tub 20 is formed through injection molding. Bearings 52 areinstalled between the bearing housing 50 and the drive shaft 42 so as toefficiently rotate the drive shaft 42.

The drive shaft 42 is disposed between the drum 30 and the motor 40. Oneend of the drive shaft 42 is connected to the rear plate 33 of the drum30, and the other end of the drive shaft 42 is extended to the outsideof the rear wall of the tub 20. When the motor 40 drives the drive shaft42, the drum 30 connected to the drive shaft 42 is rotated around thedrive shaft 42.

A plurality of through holes 34 to circulate wash water is formedthrough the circumferential surface of the drum 30, and a plurality oflifters 35 to tumble laundry during rotation of the drum 30 is installedon the inner circumferential surface of the drum 30.

During the washing and rinsing cycles, the motor 40 rotates the drum 30at a low velocity in regular and reverse directions. As the laundry inthe drum 30 is repeatedly tumbled due to rotation of the drum 30,contaminants are removed from the laundry.

During the spin-drying cycle, the motor 40 rotates the drum at a highvelocity in one direction, thereby removing water from the laundry usingcentrifugal force applied to the laundry.

A device which allows water supplied from the external water supplysource (not shown) to pass through the inside of the device and includesat least one structure except for internal channels may be defined as awater supply unit. That is, the water supply unit is provided with aninlet and an outlet and includes internal channels and structuresdiscriminated from the channels, and at least one of the inlet and theoutlet is connected to the water supply hose 60. For example, since thedetergent supply device 100 is provided with inlets 129 and an outlet131 and includes internal channels along which water flows andstructures discriminated from the channels, for example, such as asiphon device 147, a detergent container 140, and guide rails 132, andthe inlets 129 of the detergent supply device 100 are connected to thewater supply hoses 60, the detergent supply device 100 may be referredto as a water supply unit. On the other hand, since a Y-shaped connectoror a T-shaped connector mounted on the water supply hoses 60 includes nostructure discriminated from internal channels in addition to internalwalls forming the internal channels, such a connector may not bereferred to as a water supply unit. In addition to the detergent supplydevice 100, a steam generator (not shown), a backflow prevention device(not shown), and water supply valves 62 may be referred to as watersupply units.

Detergents or contaminants removed from the laundry may stick to thedoor glass 13 during the washing and rinsing cycles. When the laundry istaken out of the drum 30 after washing of the laundry, the laundry comesinto contact with the door glass 13 and thus may be re-contaminated withthe detergents or the contaminants.

Therefore, the washing machine 1 includes a door washing hose 61 toguide water from the water supply source (not shown) to the door glass13 so as to wash the door glass 13. A spray hole 11 a to spray watertoward the door glass 13 is formed on the gasket 11, and the doorwashing hose 61 is connected to the spray hole 11 a. The door washinghose 61 may branch off from the water supply hose 60 or be connected tothe external water supply source (not shown) separately from the watersupply hoses 60.

In order to allow the door washing hose 61 to branch off from the watersupply hose 60 or to connect the door washing hose 61 to the externalwater supply source (not shown) separately from the water supply hoses60, a separate component is required. Particularly, if a separate branchcomponent, for example, such as the Y-shaped connector or the T-shapedconnector, is mounted on the water supply hose 60 and then the doorwashing hose 61 is connected to the separate branch component,production costs may be increased and water leakage at a connectionportion between the components may occur.

Therefore, the washing machine 1 includes the detergent supply device100 provided with a branch pipe 150 to supply water to the door washinghose 61.

FIG. 2 is an exploded perspective view of the detergent supply device ofthe washing machine in accordance with the embodiment, FIG. 3A is a planview illustrating water supply channels of the detergent supply deviceshown in FIG. 2, and FIG. 3B is a cross-sectional view illustrating aninlet pipe and a branch pipe of the detergent supply device shown inFIG. 2.

As shown in FIGS. 2 to 3B, the detergent supply device 100 includes ahousing 101, the front surface of which is opened, and a detergentcontainer 140 detachably connected to the front surface of the housing101. The detergent container 140 includes detergent storage parts 143,144, 145 and 146 formed so as to be divided from one another by a frontsurface 141 a, a rear surface 141 d, side walls 141 b and 141 c of atray 141, and diaphragms 142 a, 142 b and 142 c.

The housing 101 includes an upper housing part 120, a lower housing part130, and a cover 110 to cover the upper portion of the upper housingpart 120. First, second, third and fourth water supply parts 123, 124,125 and 126 divided from one another by a plurality of diaphragms, areprovided within a rectangular side wall 122 on the front surface of theupper housing part 120. The first, second, third and fourth water supplyparts 123, 124, 125 and 126, are provided with inlets 129 a, 129 b, 129c and 129 d respectively connected to water supply valves 62 a, 62 b, 62c and 62 d and the water supply hoses 60.

A plurality of through holes 128 to supply water, introduced into therespective water supply parts 123, 124, 125 and 126 through the inlets129 a, 129 b, 129 c and 129 d, to the inside of the detergent container140, are provided on the bottom of the upper housing part 120. Thethrough holes 128 are properly distributed along channels 123 b, 124 b,125 b and 126 d formed in the respective water supply parts 123, 124,125 and 126.

The lower housing part 130 is provided with an outlet 131 connected tothe connection hose 64 shown in FIG. 1 so as to supply water havingpassed through the through holes 128 of the upper housing part 120 tothe tub 20 shown in FIG. 1. The outlet 131 is sloped downwards at therear portion thereof such that the water easily flows to the outlet 131.Guide rails 132 are provided on both side surfaces of the lower housingpart 130 such that the detergent container 140 may be slidably connectedto the lower housing part 130 along the guide rails 132.

The detergent container 140 includes the tray 141, the upper surfaceportion of which is opened, and the tray 141 is divided into a mainwashing detergent storage part 143, a bleaching detergent storage part145, and a rinsing detergent storage part 146 by the front surface 141a, the rear surface 141 d, the side walls 141 b and 141 c, and thediaphragms 142 a, 142 b and 142 c. Further, a preliminary washingdetergent storage part 144 used during a preliminary washing cycle maybe selectively installed.

The rear portion of the main washing detergent storage part 143 isopened such that supplied water is discharged to the outlet 131 via thefirst water supply part 123 and the through holes 128. A siphon device147 to discharge supplied water to the outlet 131 is formed on thebottom of each of the bleaching detergent storage part 145 and therinsing detergent storage part 146. The bottoms of the main washingdetergent storage part 143, the preliminary washing detergent storagepart 144, the bleaching detergent storage part 145, and the rinsingdetergent storage part 146 are sloped downwards at the rear portionsthereof.

Water supplied from the external water supply source through the watersupply valves 62 and the water supply hoses 60 is supplied to the insideof the detergent supply device 100 through the respective inlets 129 a,129 b, 129 c, and 129 d.

As the water supplied to the inside of the detergent supply device 100passes through the first, second, third, and fourth water supply parts123, 124, 125 and 126 and the detergent storage parts 143, 144, 145, and146 according to the washing, rinsing, and spin-drying cycles, the wateris mixed with detergents and is then supplied to the tub 20 shown inFIG. 1 through the outlet 131 and the connection hose 64.

During the preliminary washing cycle, water supplied through the watersupply valve 62 b is introduced into the through holes 128 disposed inthe second water supply part 124. The water is mixed with a detergentstored in the preliminary washing detergent storage part 144 and is thensupplied to the tub 20.

During the main washing cycle, water supplied through the water supplyvalves 62 a and 62 c is introduced into the through holes 128 disposedin the first water supply part 123. The water is mixed with a detergentstored in the main washing detergent storage part 143 and is thensupplied to the tub 20.

The rinsing cycle is repeated twice. During the first rinsing cycle,water supplied through the water supply valve 62 d is mixed with ableaching agent via the third water supply part 125 and the bleachingdetergent storage part 145 and is then supplied to the tub 20. Duringthe second rinsing cycle, water supplied through the water supply valves62 a and 62 d is mixed with a fabric softener via the fourth watersupply part 126 and the rinsing detergent storage part 146 and is thensupplied to the tub 20.

The detergent supply device 100 is provided with first, second, third,and fourth inlet pipes 127 a, 127 b, 127 c, and 127 d protruded outwardso as to connect the respective inlets 129 a, 129 b, 129 c, and 129 d tothe water supply hoses 60.

Since the branch pipe 150 is connected to the door washing hose 61,water introduced into the door washing hose 61 through the branch pipe150 may contain no detergent such that water containing no detergent isintroduced into the branch pipe 150. Therefore, the branch pipe 150 maybranch off from at least one of the first, second, third, and fourthinlet pipes 127 a, 127 b, 127 c, and 127 d.

A branch hole 151 is formed on the side wall of the at least one of thefirst, second, third, and fourth inlet pipes 127 a, 127 b, 127 c and 127d, and the branch pipe 150 is extended to the outside of the at leastone of the first, second, third, and fourth inlet pipes 127 a, 127 b,127 c, and 127 d so as to communicate with the branch hole 151. Thebranch pipe 150 may be fixed to the outside of the at least one of thefirst, second, third, and fourth inlet pipes 127 a, 127 b, 127 c, and127 d so as to be extended downwards. This is carried out inconsideration of an assembly process between the door washing hose 61and the branch pipe 150 and overall space utility.

A portion of water supplied to the first, second, third, or fourth inletpipe 127 a, 127 b, 127 c, and 127 d through each of the water supplyhoses 60 branches off into the branch pipe 150 and is then introducedinto the door washing hose 61, and the remaining portion of the water issupplied to the tub 20 shown in FIG. 1 via the detergent supply device100. Since washing or rinsing of laundry requires a greater amount ofwater than that of water required during washing of the door glass 13,an amount of water supplied to the tub 20 may be greater than an amountof water introduced into the door washing hose 61. Therefore, across-sectional area of the branch pipe 150 may be smaller than across-sectional area of the inlet pipes 127 a, 127 b, 127 c, and 127 d.

The branch pipe 150 may be connected to the second inlet pipe 127 b suchthat a portion of water introduced through a second water supply hose 60b branches off. Therefore, a portion of water introduced into the secondinlet pipe 127 b during the preliminary washing cycle may be supplied tothe door washing hose 61 through the branch pipe 51. Since thepreliminary washing cycle is carried out prior to the main washing cycleand less water is introduced into the second inlet pipe 127 b than intothe first inlet pipe 127 a throughout the overall process from thewashing cycle to the spin-drying cycle, the branch pipe 150 branches offfrom the second inlet pipe 127 b, thereby allowing water to be moreeffectively used. Further, the second water supply valve 62 b is openedso that water is introduced into the door washing hose 61 prior tocompletion of the spin-drying cycle. Here, a length of the second inletpipe 127 b is longer than that of the first, third, and fourth inletpipes 127 a, 127 c, and 127 d so that the branch pipe 150 may be fixedto the side wall of the second inlet pipe 127 b.

FIG. 4A is a cross-sectional view illustrating a main configuration of awashing machine in accordance with another embodiment and FIG. 4B is aview illustrating connection between a backflow prevention device and adetergent supply device of the washing machine in accordance with theembodiment.

As shown in FIGS. 4A and 4B, a washing machine 2 in accordance with thisembodiment includes a main body 10, a tub 20, water supply hoses 60,water supply valves 62, a detergent supply device 100, and a doorwashing hose 61. Such components in this embodiment are substantiallythe same as or similar to those in the embodiment shown in FIG. 1, and adetailed description thereof will thus be omitted because it isconsidered to be unnecessary.

Water containing detergents or contaminants may flow backward along thewater supply hoses 60 and be introduced into a water supply source (notshown). In order to prevent such a backflow, the washing machine 2includes a backflow prevention device 200 mounted on the water supplyhose 60.

Since the backflow prevention device 200 is provided with an inlet andan outlet and includes internal channels along which water flows and astructure discriminated from the channels, such as a moving member 242(with reference to FIG. 5), and the inlet of the backflow preventiondevice 200 is connected to the water supply hose 60, the backflowprevention device 200 corresponds to a water supply unit. Therefore, thebackflow prevention device 200 includes a branched structure connectedto the door washing hose 61.

The backflow prevention device 200 may be mounted on at least one offirst, second, third, and fourth water supply hoses 60 a, 60 b, 60 c,and 60 d. For example, if the backflow prevention device 200 is mountedon the fourth water supply hose 60 d, the backflow prevention device 200prevents a bleaching agent or a fabric rinse used in rinsing of laundryfrom flowing backward along the fourth water supply hose 60 d and beingintroducing into the water supply source. Although the backflowprevention device 200 is mounted on any one of the water supply hoses 60a, 60 b, 60 c, and 60 d, the backflow prevention device 200 may preventcontamination of the water supply source. However, since the mainwashing cycle is generally carried out while the washing machine 2 isused, the backflow prevention device 200 may be mounted on the firstwater supply hose 60 a.

A portion of water introduced into the backflow prevention device 200branches off within the backflow prevention device 200 and is introducedinto the door washing hose 61. The water introduced into the doorwashing hose 61 is guided to the door glass 31 and is used to wash thedoor glass 31.

Supply of water to the water supply hose 60 on which the backflowprevention device 200 is mounted may be carried out before thespin-drying cycle or during the spin-drying cycle. Hereinafter, thebackflow prevention device 200 mounted on the first water supply hose 60a will be described.

The first water supply valve 62 a may be opened so as to supply water tothe first water supply hose 60 a. A portion of the water supplied to thefirst water supply hose 60 a is branched off within the backflowprevention device 200 and is supplied to the detergent supply device100, and the remaining portion of the water is guided to the door glass13 through the door washing hose 61. The water supplied to the detergentsupply device 100 is supplied to the tub 20 through the connection hose64, and the water guided to the door glass 13 is used to wash the doorglass 13. Here, an amount of the water branched off into the doorwashing hose 61 may be about 40% of the total amount of water suppliedto the backflow prevention device 200.

A control unit (not shown) opens the first water supply valve 62 a so asto supply water to the first water supply hose 60 a at least fiveminutes before the spin-drying cycle is terminated. A time for whichwater supply is carried out is about 10 seconds, and an amount of watersupplied to the first water supply hose 60 a for this time may be about1 liter (1 l). 1 l of water is divided within the backflow preventiondevice 200 so that 600 ml of water is supplied to the tub 20 through thedetergent supply device 100 and 400 ml of water is guided to the doorglass 13 through the door washing hose 61 and used to wash the doorglass 13. Here, the water supplied to the tub 20 is discharged to theoutside through the spin-drying cycle.

FIG. 5 is an exploded perspective view of the backflow prevention devicein accordance with the embodiment and FIG. 6A is a cross-sectional viewof the backflow prevention device in accordance with the embodiment.

As shown in FIGS. 5 and 6A, the backflow prevention device 200 includesa case 210 provided with an inlet 261 and an outlet 262 and a backflowblocking unit 240 disposed within the case 210.

The case 210 forms the external appearance of the backflow preventiondevice 200, and a backflow prevention part 260 communicating with theinlet 261 and the outlet 262 is provided within the case 210. Thebackflow blocking unit 240 is disposed in the backflow prevention part260.

The case 210 includes a nozzle part 220 on which the inlet 261 isformed, and a connector part 230 on which the outlet 262 is formed. Thebackflow prevention part 260 is defined by the inner walls of the nozzlepart 220 and the connector part 230. The nozzle part 220 and theconnector part 230 are coupled through screw connection, thus formingthe case 210. In order to achieve screw connection, screw threads 222and 234 having a corresponding shape may be formed on the nozzle part220 and the connector part 230.

In order to prevent water leakage at a connection area between thenozzle part 220 and the connection part 230, a sealing member 250 may bedisposed between the nozzle part 220 and the connector part 230. Thesealing member 250 may be a ring-shaped packing made of an elasticmaterial, for example, such as rubber.

The inlet 261 is formed at one side of the nozzle part 220. The inlet261 has a circular cross-section. The inlet 261 communicates with thewater supply hose 60, and water in the water supply hose 60 isintroduced into the backflow prevention part 260 through the inlet 261.

The nozzle part 220 includes an inlet pipe 221 communicating with theinlet 261 and provided with one end fixed to the nozzle part 220 and theother end protruded to a designated length to the outside of the nozzlepart 220. The inlet pipe 221 may be formed integrally with the nozzlepart 220, or be formed separately and is then connected to the nozzlepart 220.

The water supply hose 60 is made of an elastic material, for example,such as rubber, and is connected to the inlet pipe 221 such that thewater supply hose 60 surrounds a part of one end of the inlet pipe 221.Here, a clamp 63 to fix the water supply hose 60 to the inlet pipe 221may be mounted.

An inlet channel 270 is defined by the inlet 261 and the inlet pipe 221.Water supplied through the water supply hose 60 is introduced into thebackflow prevention part 260 via the inlet channel 270. The waterintroduced into the backflow prevention part 260 is discharged to theoutside through the outlet 262.

The outlet 262 is formed at one side of the connector part 230. Theconnector part 230 includes an outlet pipe 231 communicating with theoutlet 262 and provided with one end fixed to the connector part 262 andthe other end protruded to a designated length to the outside of theconnector part 230. The outlet pipe 262 may be formed integrally withthe connector part 230, or be formed separately and is then connected tothe connector part 230.

An outlet channel 280 is defined by the outlet 262 and the outlet pipe231. The water introduced into the backflow prevention part 260 isdischarged to the outside through the outlet channel 280.

The outlet 262 is divided into a first outlet 263 and a second outlet264. The water introduced into the backflow prevention part 260 isbranched off by the first outlet 263 and the second outlet 264 and isthen discharged to the outside. Water discharged through the firstoutlet 263 is supplied to the tub 20 through the water supply hose 60.Here, the second outlet 264 is a branch outlet.

The outlet pipe 231 is divided into a first outlet pipe 232communicating with the first outlet 263 and protruded to a designatedlength to the outside of the connector part 230, and a second outletpipe 233 communicating with the second outlet pipe 264 and protruded toa designated length to the outside of the connector part 230. A firstoutlet channel 281 is defined by the first outlet 262 and the firstoutlet pipe 232, and a second outlet channel 282 is defined by thesecond outlet 264 and the second outlet pipe 233. Such a channelbranched structure of the backflow prevention device 200 reducesproduction costs, as compared with mounting of a separate branchcomponent on the water supply hose 60, and eliminates additional waterleakage points generated due to mounting of the separate branchcomponent. Here, the second outlet pipe 233 is a branch pipe.

Amounts of water flowing along the first outlet channel 281 and thesecond outlet channel 282 are determined by cross-sectional areas of thefirst outlet 263 and the second outlet 264. Therefore, thecross-sectional areas of the first outlet 263 and the second outlet 264are adjusted according to usage purposes of the respective channels 281and 282.

The first outlet channel 281 is connected to the water supply hose 60.Therefore, water supplied to the water supply hose 60 may sequentiallypass through the inlet channel 270, the backflow prevention part 260 andthe first outlet channel 281, and then be supplied to the tub 20.

The water supply hose 60 is connected to the first outlet pipe 232 suchthat the water supply hose 60 surrounds a part of one end of the firstoutlet pipe 232. In order to fix the water supply hose 60 to the firstoutlet pipe 232, the clamp 63 is provided.

The second outlet 264 is formed on the side wall of the first outletpipe 232, and the second outlet pipe 233 is fixed to the side wall ofthe first outlet pipe 232 and protruded to the outside of the connectorpart 230. Therefore, a portion of water passing through the first outletpipe 232 branches off into the second outlet 264 and is introduced intothe second outlet pipe 233.

The second outlet pipe 233 is connected to the door washing hose 61.Therefore, water supplied to the water supply hose 60 may sequentiallypass through the inlet channel 270, the backflow prevention part 260 andthe second outlet channel 282, and then be guided to the door glass 13.

The door washing hose 61 is connected to the second outlet pipe 233 suchthat the door washing hose 61 surrounds a part of one end of the secondoutlet pipe 233. In order to fix the door washing hose 61 to the secondoutlet pipe 233, a clamp 61 a is provided.

The backflow blocking unit 240 is disposed within the backflowprevention part 260 and prevents water introduced into the backflowprevention part 260 from flowing backward and being introduced into theinlet channel 270. The backflow blocking unit 240 includes a movingmember 242 movably disposed in the backflow prevention part 260.

The moving member 242 moves within the backflow prevention part 260 dueto a flow of water within the backflow prevention part 260, therebyselectively opening and closing the inlet 261. When water is introducedinto the inlet 261 through the inlet channel 270, the moving member 242moves in the direction of the outlet 262 and thus opens the inlet 261.On the other hand, when water is introduced into the outlet 262 throughthe outlet channel 280, the moving member 242 moves in the direction ofthe inlet 261 and thus closes the inlet 261.

Since the cross-section of the inlet 261 is circular, the moving member242 may be a spherical ball having a designated diameter so as to beclosely adhered to the inlet 261. The diameter of the ball is at leastgreater than the diameter of the inlet 261.

The backflow blocking unit 240 includes an inclined surface part 241inclined toward the inlet 261 so as to guide the moving member 242 tothe inlet 261 when water introduced into the backflow prevention part260 moves from the outlet 262 to the inlet 261.

One end of the inclined surface part 241 is separated from the outlet262 by a designated distance and the other end of the inclined surfacepart 241 is located on the frame of the inlet 261. Further, the inclinedsurface part 241 may be formed on at least one of the inner wall of thenozzle part 220 and the inner wall of the connector part 230.

While the inlet 261 is selectively opened and closed, the outlet 262needs to maintain an opened state at all times. Since the moving member242 moves in the flow direction of water within the backflow preventionpart 260, the moving member 242 may close the outlet 262 when the waterflows from the inlet 261 to the outlet 262. Therefore, in order toprevent the moving member 242 from closing the outlet 262, the backflowblocking unit 240 includes a separation member 243 to separate themoving member 242 from the outlet 262 by a designated distance so as toprevent the moving member 242 from closing the outlet 262.

The separation member 243 is disposed around the outlet 262 andprotruded to the inside of the backflow prevention part 260 by adesignated distance. Therefore, the moving member 242 may not approachthe outlet 262 by the designated distance or less due to the separationmember 243. The separation member 243 may be fixed to one of the nozzlepart 220 and the connector part 230. The separation member 243 has theshape of a protruded rib.

FIG. 6B is a cross-sectional view of a backflow prevention device inaccordance with a further embodiment.

As shown in FIG. 6B, a first outlet 263 and a second outlet 264 directlycommunicate with a backflow prevention part 260 and a second outlet pipe233 is formed separately from a first outlet pipe 232. The first outletpipe 232 and the second outlet pipe 233 are fixed to a connector part230 by a designated distance between the first outlet pipe 232 and thesecond outlet pipe 233. Here, a plurality of separation members 243 isprovided around the first outlet pipe 232 and the second outlet pipe233, respectively.

FIGS. 7A and 7B are views illustrating operation of a backflowprevention device in accordance with one embodiment.

As shown in FIG. 7A, when water is introduced into the backflowprevention part 260 through the inlet channel 270, the moving member 242moves to the outlet 262 due to a water flow. Since the separation member243 is disposed around the outlet 262, the moving member 242 does notclose the outlet 262. Therefore, the water introduced into the backflowprevention part 260 is discharged to the outside through the outletchannel 280 regardless of movement of the moving member 242. Here, thewater is branched off into the first outlet channel 281 and the secondoutlet channel 282. Water introduced into the first outlet channel 281is supplied to the tub 20, and water introduced into the second outletchannel 282 is guided to the door glass 13 shown in FIG. 1 and used towash the door glass 13.

As shown in FIG. 7B, water may flow backward through the outlet 262 andbe introduced into the backflow prevention part 260. The moving member242 together with water flowing toward the inlet 261 moves to the inlet261. The moving member 242 moves along the inclined surface part 242 andcloses the inlet 261 and thus water within the backflow prevention part260 does not flowing toward the inlet channel 270.

When the moving member 242 closes the inlet 261, a pressure differencebetween the inlet channel 270 and the backflow prevention part 260occurs. Therefore, force in the direction of the inlet channel 270 isapplied to the moving member 242 due to such a pressure difference, andthe moving member 242 maintains the state of being closely adhered tothe inlet 261 by the force.

When the water introduced into the backflow prevention part 260 isdischarged to the outside through the outlet 262, the force applied tothe moving member 242 is eliminated, and thus the moving member 242opens the inlet 261.

As is apparent from the above description, a washing machine inaccordance with one embodiment allows a branch pipe provided on a watersupply unit, for example, such as a detergent supply device or abackflow prevention device, to guide water to a door glass, therebymaintaining the door glass in a clean state. Further, the washingmachine does not use a separate branched structure, thereby reducing thenumber of necessary parts and thus reducing production costs. Moreover,the washing machine reduces the number of the necessary parts and thussimplifies an assembly process, and reduces the number of water leakagepoints between the parts and thus has improved durability.

Further, the washing machine prevents a backflow of water along a watersupply hose, thereby preventing water containing detergents orcontaminants from flowing backward into an external water supply sourceduring operation of the washing machine. Therefore, environmentalproblems, for example, such as contamination of the water supply sourcedue to the backflow, may be solved.

Although a few embodiments have been shown and described, it would beappreciated by those skilled in the art that changes may be made inthese embodiments without departing from the principles and spirit ofthe invention, the scope of which is defined in the claims and theirequivalents.

1. A washing machine comprising: a main body; a tub provided within themain body; a water supply hose connected to a water supply source tosupply water to the tub; a water supply unit including channels definedby at least one inlet and at least one outlet and at least one structurediscriminated from the channels, at least one of the at least one inletand the at least one outlet being connected to the water supply hose;and a branch pipe provided on the water supply unit to allow a portionof water introduced into the water supply unit to branch off and thus bedischarged to the outside of the water supply unit.
 2. The washingmachine according to claim 1, wherein the water supply unit is adetergent supply device provided to supply detergents to the tub.
 3. Thewashing machine according to claim 2, wherein: the detergent supplydevice includes at least one inlet pipe protruded from the at least oneinlet so as to be connected to the water supply hose; and the branchpipe branches off from the at least one inlet pipe.
 4. The washingmachine according to claim 3, wherein: the at least one inlet includes afirst inlet into which water is introduced during a main washing cycleand a second inlet into which water is introduced during a preliminarywashing cycle; the at least one inlet pipe includes a first inlet pipeprotruded from the first inlet and a second inlet pipe protruded fromthe second inlet; and the branch pipe is fixed to the second inlet pipeso as to communicate with the second inlet pipe.
 5. The washing machineaccording to claim 2, wherein the branch pipe is extended downwards. 6.The washing machine according to claim 3, wherein a cross-sectional areaof the branch pipe is smaller than a cross-sectional area of the atleast one inlet pipe from which the branch pipe branches off.
 7. Thewashing machine according to claim 4, wherein a length of the secondinlet pipe is greater than a length of the first inlet pipe.
 8. Thewashing machine according to claim 1, wherein the water supply unit is abackflow prevention device provided to prevent wash water from flowingbackward and being introduced into the water supply source.
 9. Thewashing machine according to claim 8, wherein: the backflow preventiondevice includes a case provided with the at least one inlet and the atleast one outlet and a backflow blocking unit disposed within the caseto block a backflow of water into the at least one inlet; and the atleast one inlet is connected to the water supply hose and the at leastone outlet is a plurality of outlets provided so as to discharge waterin different directions.
 10. The washing machine according to claim 9,wherein the case includes a nozzle part provided with the at least oneinlet and a connector part provided with the at least one outlet. 11.The washing machine according to claim 10, wherein the nozzle part andthe connector part are coupled with each other by screw connection. 12.The washing machine according to claim 9, wherein the backflow blockingunit includes a moving member moving within the case according to awater flow so as to selectively open and close the at least one inlet.13. The washing machine according to claim 12, wherein the backflowblocking unit further includes a separation member disposed around theat least one outlet so as to separate the moving member from the atleast one outlet.
 14. The washing machine according to claim 12, whereinthe backflow blocking unit further includes an inclined surface partformed on the inner wall of the case so as to guide the moving member tothe at least one inlet.
 15. The washing machine according to claim 12,wherein: the moving member is a spherical ball having a designateddiameter; and the diameter of the ball is greater than a diameter of theat least one inlet.
 16. The washing machine according to claim 12,wherein the moving member is closely adhered to the at least one inletdue to water pressure and thus closes the at least one inlet when waterflows backward in the direction of the at least one inlet.
 17. Thewashing machine according to claim 9, wherein: the case includes anoutlet pipe connected to one of the plurality of outlets and protrudedto the outside of the case; and at least one of the plurality of outletsis formed on the side wall of the outlet pipe.
 18. The washing machineaccording to claim 17, wherein the branch pipe communicates with the atleast one of the plurality of outlets formed on the side wall of theoutlet pipe and is protruded to the outside of the outlet pipe.
 19. Thewashing machine according to claim 1, further comprising: a door to openand close the main body; and a door washing hose to guide water to therear surface of the door, wherein the branch pipe is connected to thedoor washing hose.
 20. A washing machine comprising: a main body; a tubprovided within the main body; a water supply hose connected to a watersupply source to supply water to the tub; and a backflow preventiondevice mounted on the water supply hose to prevent wash water in the tubfrom flowing backward and being introduced into the water supply source,wherein: the backflow prevention device includes a backflow preventionpart provided with an inlet and an outlet, an inlet channelcommunicating with the inlet, outlet channels communicating with theoutlet, and a backflow blocking unit disposed in the backflow preventionpart to prevent water from flowing backward into the inlet channel; andthe outlet channels include a first outlet channel and a second outletchannel formed separately from the first outlet channel.
 21. The washingmachine according to claim 20, wherein the second outlet channelbranches off from the first outlet channel.
 22. The washing machineaccording to claim 20, wherein the second outlet channel directlycommunicates with the backflow prevention part.
 23. A washing machinecomprising: a main body; a tub provided within the main body; a watersupply hose connected to a water supply source to supply water to thetub; and a detergent supply device connected to the water supply hose tosupply detergents to the tub, wherein: the detergent supply deviceincludes a housing, inlet pipes protruded to the outside of the housingso as to be connected to the water supply hose, and a branch pipebranching off from at least one of the inlet pipes.
 24. A washingmachine comprising: a main body provided with an inlet through whichlaundry is put into the main body; a tub formed within the main body andprovided with an opening corresponding to the inlet; a door to open andclose the inlet; a gasket to shield a space between the inlet and theopening; a water supply hose connected to a water supply source tosupply water to the tub; a door washing hose connected to a wash waterspray hole formed on the gasket; and a backflow prevention devicemounted on the water supply hose to prevent wash water from flowingbackward along the water supply hose and being introduced into the watersupply source, wherein: the backflow prevention device includes a case,an inlet pipe and an outlet pipe communicating with the inside of thecase and protruded to the outside of the case, a backflow blocking unitdisposed at the inside of the case, and a branch pipe forming a channelseparately from the outlet pipe; and the branch pipe is connected to thedoor washing hose.
 25. A detergent supply device comprising: a housing;a detergent container provided within the housing so as to receivedetergents; inlet pipes protruded to the outside of the housing so as tosupply water to the detergent container; and a branch pipe fixed to atleast one of the inlet pipes so as to allow a portion of waterintroduced into the inlet pipe to branch off.
 26. A backflow preventiondevice comprising: a case including a nozzle part provided with an inletand a connector part provided with an outlet; a backflow blocking unitdisposed within the case to prevent water within the case from flowingbackward and being introduced into the inlet; and a branch hole forminga channel separately from the outlet, wherein the nozzle part and theconnector part are coupled with each other by screw connection.